Most hazardous elements contribute significantly to contamination of agricultural soils. Their content in the soil increases above background level due to anthropogenic influences as industry ballast and transportation and energy production, especially in the surface layer of the humus horizon. Accumulation of hazardous elements in the soil has a significant ecological impact on the speed of the elemental cycling. Due to binding to primary agricultural products they can pass into the food chain.
Soil samples from a dump in the Central Bohemia were collected for determination of selected hazardous elements. Instrumental neutron activation analysis (INAA) and instrumental photon activation analysis (IPAA) were used for the assay of elements such as As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, V, and Zn. Results obtained by the radioanalytical methods were compared with the regulatory values applicable in the Czech Republic.
As expected, the content of hazardous elements in dump soils in the Central Bohemia increases. The amount of these elements is several times higher than the maximum permissible limits. It suggests their anthropogenic origin, probably from the operation of former coal mines and the Poldi Steelworks. Most of the hazardous elements are included in the group of extraneous substances that can significantly contribute to contamination of agricultural soils. A potential long term risk is expected because free access to this area is not disabled.
The study has been supported by the Ministry of Education, Youth and Sports of the Czech Republic within the projects LM2015056 (CANAM - Center of Accelerators and Nuclear Analytical Methods) and LM2015074 (Nuclear Research Reactors LVR-15 and LR-0), and by the Czech Science Foundation within the project P108/12/G108.